I'm not exactly sure what you mean by "FTP", but from your post, it looks like some mass-scale file sharing. I am one of the ardent opponents to file sharing. It kills the music industry. Why do you think classical music is going down the drain? Because nobody buys CDs anymore, they just get it from others.(Maybe I misinterpreted "FTP", if so, ignore what I said)
So what if they don't record anything anymore, all the great works have already been recorded, so it doesn't matter to me if they don't record the chopin etudes for the hundred and fifth time.
There already is a BitTorrent site for piano related material: https://pianosheets.org/
Terrible.
For mp3s, there are newsgroups and IRC. Both have lots but it takes a while to learn how to use each.
Sorry to dig up an old thread, but why do you say this? Have you heard of #mp3_classical on Undernet? They have so much to offer; I've never left the channel without what I was looking for.